The role of cytosolic sialidase in developing enamel organs.

胞质唾液酸酶在牙釉质器官发育中的作用。

• 批准号: 09671845
• 负责人: AKITA Hirotoshi
• 金额: $ 2.05万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09671845/
• 关键词: sialoglycoconjugate; cytosolic sialidase; enamel organ; in situ hybridization; immunocytochemistry; lectin-cytochemistry; transmission eletron microscope; rat; 歯胚上皮; 免疫組織化学; レクチン組織化学; 骨格筋細胞; 上皮性歯胚

We obtained following results in in situ hybridization, immunocytochemical, and lectincytochemical studies of rat molar tooth germs.(1) in situ hybridization study : The level of cytosolic sialidase-mRNAs changed largely with cell differentiation. It was high in the oral epithelium, outer and inner enamel epithelium, and dental papilla. It was very low or barely detectable in the stellate reticulum and transitional cells between the oral epithelium and the outer enamel epithelium, suggesting its steep drop in transition. Although the overall image of the mRNA expression was high in dental papilla, the mesenchymal cells expressed different levels of the mRNAs from each other.(2) immunocytochemical study : Every cell expressed high levels of cytosolic sialidase-protein in the oral epithelium, enamel organ and dental papilla. The enzyme protein was localized in the cytoplasm, nucleoplasm and mitochondrial matrix of each cell. Its Iocalization pattern was very similar to that in skeletal m … More uscle cells of rats, suggesting it being ubiquitous in many types of cells. Based on the number of immunogold particles, the amount of the enzyme protein did not largely change in cells during the course of cell differentiation. In this point of view the expression of the enzyme protein was different from that of the mRNA.(3) lectin-cytochemical study : Lectin (Limax flavus)-binding sites were numerous on the cell surface and in the extracellular matrix of tooth germs. However the number of them were small in the cytoplasm. We examined whether a small number of those binding sites were meaningful or not. An inhibitory sugar was effective in decreasing the binding sites at about a half level, indicating the presence of putative cytoplasmic sialoglycoconjugates. The possibility of non-specific lectin binding to the cytoplasm remains to be excluded by conducting a supplementary experiment in which the binding sites are expected to decrease in tissue sections digested by cytosolic sialidase. Less

本研究对大鼠磨牙牙胚进行了原位杂交、免疫细胞化学和凝集素细胞化学研究。(1)原位杂交研究：胞浆唾液酸酶-mRNAs水平随细胞分化程度变化较大。在口腔上皮、外釉上皮、内釉上皮、牙乳头中含量较高。在星状网和口腔上皮与外釉上皮之间的过渡细胞中很低或几乎检测不到，提示其在过渡过程中急剧下降。免疫细胞化学研究：口腔上皮、釉质器官和牙乳头细胞胞浆唾液酸酶蛋白表达水平均较高。该酶蛋白定位于细胞的胞浆、核浆和线粒体基质中。它的定位模式与骨骼m…非常相似大鼠肾小球体细胞较多，提示其在多种细胞中普遍存在。根据免疫金粒的数量，在细胞分化过程中，细胞内的酶蛋白含量没有太大变化。凝集素细胞化学研究：在牙胚的细胞表面和细胞外基质中有大量的凝集素(Limax Huang Us)结合部位。但胞质内数量较少。我们检查了这些结合位点中的一小部分是否有意义。抑制糖有效地减少了大约一半的结合部位，这表明可能存在细胞质唾液酸糖偶联物。非特异性凝集素与细胞质结合的可能性仍有待通过进行补充实验来排除，在该实验中，被胞浆唾液酸酶消化的组织切片中的结合部位预计会减少。较少

项目成果

Kazuo Hanzawa (米澤 和雄): "Oral manifestations and long-trem observations of active Paget's disease of bone." J.Bone Miner.Metab.16・4. 264-270 (1998)

Kazuo Hanzawa (Kazuo Yonezawa)：“活动性佩吉特骨病的口腔表现和长期观察。J.Bone Miner.Metab.16・4 (1998)。

Tadashi Wada: "Cloning, expression, and chromosomal mapping of a human ganglioside sialidase"Biochemical and Biophysical Research Communications. 261・1. 21-27 (1999)

和田正：“人神经节苷脂唾液酸酶的克隆、表达和染色体定位”《生物化学和生物物理研究通讯》261·1（1999）。